There is a dispensing device of which patent application was filed by the applicant of the present application and matured into a patent. In the dispensing device, a dispensing tip engages with and attaches to a lower end portion of a nozzle at an attachment opening portion, and a plunger in a cylinder in communication with the nozzle is caused to slide, so that a liquid is sucked or discharged through the lower end thereof into and out of the dispensing tip (Patent Literatures 1 to 4).
However, mechanisms such as a cylinder and a plunger used in the dispensing device are highly precisely processed components such as a syringe, and in particular, the change in the volume in the cylinder is basically integral with the change in the volume in the dispensing tip, and it is necessary to transmit it to a joint portion between the plunger and a driving device of the plunger without any looseness. The sucking and discharging mechanism thereof, the dispensing tip, and the like are engaged without any leakage of gas or liquid. For this reason, a high degree of quality control may be required. More specifically, in order to engage the nozzle of the sucking and discharging mechanism with the attachment opening portion of the dispensing tip without any leakage of fluid, a high load is imposed on the dispensing tip when the nozzle is attached because of the existence of an O ring and the like provided on the attachment opening portion, and, e.g., this may destroy the dispensing tip and may cause abrasion of the nozzle, and therefore, it is necessary to exchange the nozzle and processing with a high degree of accuracy. In order to control the sucking and discharging of the dispensing tip, a cylinder having a volume corresponding to the volume of the dispensing tip is necessary, and therefore, there is a problem in that the size of the device increases when a large volume of liquid is treated.
On the other hand, in the past, a pipette has been known, which is surrounded by a wall surface such as rubber and is capable of accommodating liquid and gas therein, wherein the pipette deforms when the wall surface is manually pressed, so that the pipette sucks and discharges liquid. However, since this pipette is manually handled, a single user can handle up to only a single pipette, and it is impossible to perform processing at a time using many pipettes. The deforming of the pipette is different according to the magnitude of the force, the direction of the force, and the position where the force is applied, and therefore, in the manual pipette operation, it is difficult to perform processing that is precise in terms of amount and perform repetition with a high degree of reproducibility.
As a method of improving this, the applicant of the present application has developed a device using a deforming-type dispensing tip in which a deforming wall surface forms a portion of a wall surface accommodating liquid and gas, and the device sucks and discharges liquid by deforming the deforming wall surface (WO 2007/081000). In the device using this deforming-type dispensing tip, gas is accommodated in an accommodation unit partially formed with the deforming wall surface that deforms, and therefore, it may be necessary to rigidity hold an inlet unit connected to an accommodation unit partially having the deforming wall surface so that it does not deviate.
Further, in order to deform the deforming-type dispensing tip as intended, it may be necessary to loosely insert the deforming-type dispensing tip into a holder and the like and use it so that the deforming wall surface deforms only in a predetermined direction.
The deforming wall surface is used for a portion of an external wall of the deforming-type dispensing tip, and there is a problem in that it may be deformed or damaged, and this may increase the burden in the quality control.
It should be noted that there is a method of directly transferring from a container to a container without using any dispensing tip. Although this method simplifies the device structure, a person is required, and there is a risk of contamination because of a contact between a container and a container, and there is a problem in that a high degree of reliability cannot be obtained.